By means of the receiver for a motor vehicle, which is known from U.S. Pat. No. 4,939,791, BOCHMANN & WIEDEMANN, and corresponding German patent disclosure DE 37 41 698 (A1), an incoming program signal can be received with good quality over a relatively long driving distance without a change to a different transmitter frequency.
To travel beyond the range of the detected transmitter, however, tuning to a different transmitter frequency containing the same program signal is necessary. Consequently, it may be necessary for a transmitter search run to check several alternative frequencies for their reception quality. This can lead to interruptions in reproduction of the program signal.
German patent disclosure DE 34 32 848 C2 MIELKE, teaches that, in the Radio Data System (RDS), a list of alternative frequencies can be transmitted as contents of the data signal modulating a 57 kHz auxiliary carrier. This information is intended especially for mobile reception, and indicates at which frequencies a particular program is being broadcast by the same transmitter chain. Thereby appropriately designed receivers, having memories, will be able to store this list and thus shorten the time necessary for tuning the receiver to the prevailing optimum frequency of the list.